Mario Candamo

Maspin repression is frequently observed in prostate cancer; however, the molecular mechanism(s) causing the loss is not completely understood. Here, we demonstrate that inhibition of class I histone deacetylases (HDACs) mediates re-expression of maspin which plays an essential role in suppressing proliferation and migration capability in prostate cancer cells. Human prostate cancer LNCaP and DU145 cells treated with HDAC inhibitors, sodium butyrate, and trichostatin A, resulted in maspin re-expression. Interestingly, an exploration into the molecular mechanisms demonstrates that maspin repression in prostate tumor and human prostate cancer cell lines occurs via epigenetic silencing through an increase in HDAC activity/expression, independent of promoter DNA hypermethylation. Furthermore, transcriptional activation of maspin was accompanied with the suppression of HDAC1 and HDAC8 with significant p53 enrichment at the maspin promoter associated with an increase in histone H3/H4 acetylation. Our results provide evidence of maspin induction as a critical epigenetic event altered by class I HDACs in the restoration of balance to delay proliferation and migration ability of prostate cancer cells.

Mammary Serine Protease Inhibitor (Maspin) is a unique member of the serpin family with tumor suppressive properties. Maspin is a secreted protein encoded by a class II tumor suppressor gene, expressed in normal prostate luminal and basal cells but reduced or absent in prostate cancer. Currently, there is a consensus that maspin expression in prostate cancer is an indicator of a better prognosis and is a predictive marker for therapeutic response in prostate cancer. Experimental evidence consistently indicates that maspin suppresses tumor growth, invasion, and metastasis and promotes apoptosis in cancer cells. In this chapter, we discuss regulation of maspin expression, binding partners of maspin, and pathways through which maspin exerts its tumor suppressive properties. In addition, we summarize the progress that investigators have made in clarifying the role of maspin in prostate cancer biology and in assessing its role as a diagnostic marker and therapeutic agent.

You have accessJournal of UrologyProstate Cancer: Basic Research & Pathophysiology I1 Apr 2016MP62-09 CLASS I HDAC INHIBITION AND P53 ACTIVATION UPREGULATES MASPIN IN HUMAN PROSTATE CANCER Eswar Shankar, Rajnee Kanwal, Mario Candamo, Albert Lee, Mitali Pandey, Vijay Thakur, Pingfu Fu, Gregory MacLennan, and Sanjay Gupta Eswar ShankarEswar Shankar More articles by this author , Rajnee KanwalRajnee Kanwal More articles by this author , Mario CandamoMario Candamo More articles by this author , Albert LeeAlbert Lee More articles by this author , Mitali PandeyMitali Pandey More articles by this author , Vijay ThakurVijay Thakur More articles by this author , Pingfu FuPingfu Fu More articles by this author , Gregory MacLennanGregory MacLennan More articles by this author , and Sanjay GuptaSanjay Gupta More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2016.02.917AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Despite advances in diagnosis and treatment of prostate cancer, development of metastases remains a major clinical challenge. Maspin (SERPINB5), a unique member of the serpin (serine protease inhibitor) family, is a secreted protein encoded by a class II tumor suppressor gene, shown to regulate cell motility, invasion and regulates tumor metastasis. Loss of maspin has been frequently identified in clinical prostate cancer specimens and prostate cancer cell lines, therefore mechanistic understanding of its loss will provide new perspectives to develop novel therapeutics. METHODS Maspin expression was examined in human prostate cancer specimens of various Gleason grades, and in various human prostate cancer cell lines. Preparation of class I histone deacetylase (HDAC 1, 2, 3 and 8) knockout was achieved by infecting human prostate cancer LNCaP cells with shV and shHDAC1-8 in PLK0.1 plasmids. Human prostate cancer cells were treated with various doses of HDAC inhibitors in time- and dose-dependent manner. Migration assays were performed along with expression of maspin, and class I HDACs activity was determined by immunoblotting and ELISA assay. Immunoprecipitation and ChIP was performed in LNCaP and HDAC silenced cells to study the association between maspin and p53. RESULTS Studies performed on benign and prostate cancer specimens demonstrate progressive loss of maspin expression which correlated with increasing Gleason score. Maspin promoter methylation and deletion analysis on tissue specimens did not contribute to the loss of maspin. Treatment of human prostate cancer DU145 and LNCaP cells with sodium butyrate and trichostatin A, inhibitors of HDACs, resulted in marked increase in maspin expression and acetylation of H3/H4 histone proteins, as a consequence of downregulation of Class I HDACs. Individual knockdown of HDAC 1, 2, 3 and 8 in LNCaP cells caused an increase in maspin expression which was more pronounced in HDAC 1, 3 and 8 knockdown cells followed by increase in p53 expression. HDAC 1-8 knockout cells exhibited slow migration ability, compared to LNCaPshV cells. ChIP assay further confirmed silencing of class I HDACs in LNCaP cells facilitated the association between maspin and p53. CONCLUSIONS Our results demonstrate that loss of maspin is due to upregulation of class I HDACs and HDAC inhibitors led to increase in maspin expression and activity, in part, mediated by p53 activation in prostate cancer. © 2016FiguresReferencesRelatedDetails Volume 195Issue 4SApril 2016Page: e815 Advertisement Copyright & Permissions© 2016MetricsAuthor Information Eswar Shankar More articles by this author Rajnee Kanwal More articles by this author Mario Candamo More articles by this author Albert Lee More articles by this author Mitali Pandey More articles by this author Vijay Thakur More articles by this author Pingfu Fu More articles by this author Gregory MacLennan More articles by this author Sanjay Gupta More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

INTRODUCTION AND OBJECTIVES: Despite advances in diagnosis and treatment of prostate cancer, development of metastases remains a major clinical challenge. Maspin (SERPINB5), a unique member of the serpin (serine protease inhibitor) family, is a secreted protein encoded by a class II tumor suppressor gene, shown to regulate cell motility, invasion and regulates tumor metastasis. Loss of maspin has been frequently identified in clinical prostate cancer specimens and prostate cancer cell lines, therefore mechanistic understanding of its loss will provide new perspectives to develop novel therapeutics. METHODS: Maspin expression was examined in human prostate cancer specimens of various Gleason grades, and in various human prostate cancer cell lines. Preparation of class I histone deacetylase (HDAC 1, 2, 3 and 8) knockout was achieved by infecting human prostate cancer LNCaP cells with shV and shHDAC1-8 in PLK0.1 plasmids. Human prostate cancer cells were treated with various doses of HDAC inhibitors in timeand dose-dependent manner. Migration assays were performed along with expression of maspin, and class I HDACs activity was determined by immunoblotting and ELISA assay. Immunoprecipitation and ChIP was performed in LNCaP and HDAC silenced cells to study the association between maspin and p53. RESULTS: Studies performed on benign and prostate cancer specimens demonstrate progressive loss of maspin expression which correlated with increasing Gleason score. Maspin promoter methylation and deletion analysis on tissue specimens did not contribute to the loss of maspin. Treatment of human prostate cancer DU145 and LNCaP cells with sodium butyrate and trichostatin A, inhibitors of HDACs, resulted in marked increase in maspin expression and acetylation of H3/ H4 histone proteins, as a consequence of downregulation of Class I HDACs. Individual knockdown of HDAC 1, 2, 3 and 8 in LNCaP cells caused an increase in maspin expression which was more pronounced in HDAC 1, 3 and 8 knockdown cells followed by increase in p53 expression. HDAC 1-8 knockout cells exhibited slow migration ability, compared to LNCaPshV cells. ChIP assay further confirmed silencing of class I HDACs in LNCaP cells facilitated the association between maspin and p53. CONCLUSIONS: Our results demonstrate that loss of maspin is due to upregulation of class I HDACs and HDAC inhibitors led to increase in maspin expression and activity, in part, mediated by p53 activation in prostate cancer.